Careers
Quantitative Developer Intern
Internship · Onsite, Seoul
Plusone Trading is a small trading firm. We build software that trades on price differences across venues and borders.
This internship is about engineering judgment, not writing code. You decide what to build and how: you read the requirements, design the system, and weigh the tradeoffs. The implementation you do with AI. We need you to direct it well, and to recognize when the result is right.
That takes a real understanding of how software and systems work, not fluency in any particular stack. The work spans the whole system, from data pipelines and model deployment to order execution and the tools that watch it, and you will often be working in something you have not seen before. We want strong engineering fundamentals and the ability to get up to speed on anything fast.
The work is real. Your decisions affect systems that trade real money, and you will work next to the people who built the rest. You do not need a background in trading. You need to love engineering and learn fast.
What we're looking for
- You understand software and systems deeply, and stay curious about how they work underneath.
- You can move into an unfamiliar area and become productive quickly.
- You have strong judgment about system design and the tradeoffs between approaches.
- You build fluently with AI and can tell good output from bad.
- You are ambitious and learn because you want to understand things.
Nice to have
- You have worked with a live external system such as an exchange or a payment API, and understand what makes it hard.
- You have some exposure to crypto or market microstructure.
How to apply
The interview mirrors the work: a conversation about a real design problem, not a coding test.
If that sounds like you, email careers@plusone.uno with your résumé and a link to something you have built or designed. We read every application.